TY  - JOUR
AU  - Stelter, Jonathan
AU  - Ladd, Mark E
AU  - Fiedler, Thomas
TI  - Numerical Comparison of Local Transceiver Arrays of Fractionated Dipoles and Microstrip Antennas for Body Imaging at 7 T.
JO  - NMR in biomedicine
VL  - 35
IS  - 8
SN  - 0952-3480
CY  - New York, NY
PB  - Wiley
M1  - DKFZ-2022-00385
SP  - e4722
PY  - 2022
N1  - #EA:E020#LA:E020# /2022 Aug;35(8):e4722
AB  - Longitudinally orientated dipoles and microstrip antennas have both demonstrated superior results as RF transmit elements for body imaging at 7 T MRI and are, as of today, the most commonly used transmit elements. In this study, the performance of both antenna concepts was compared for use in local RF antenna arrays by numerical simulations. Investigated antenna elements are the fractionated dipole and the microstrip line with meander structures. Phantom simulations with a single antenna element were performed and evaluated with regard to specific absorption rate (SAR) efficiency in the center of the subject. Simulations of array configurations with 8 and 16 elements were performed with anatomical body models. Both antenna elements were combined with a loop coil to compare hybrid configurations. Singular value decomposition of the B1 + fields, RF shimming, and calculation of the voxel-wise power and SAR efficiencies were performed in regions of interest (ROIs) with varying sizes to evaluate the transmit performance. The signal-to-noise ratio (SNR) was evaluated to estimate the receive performance. Simulated data show similar transmit profiles for both antenna types in the center of the phantom (penetration depth > 20 mm). For body imaging, no considerable differences were determined for the different antenna configurations with regard to the transmit performance. Results show the advantage of 16 transmit channels compared to today's commonly used 8-channel systems (minimum RF shimming excitation error of 4.7
KW  - body imaging (Other)
KW  - dipole antennas (Other)
KW  - microstrip antennas (Other)
KW  - transmit arrays (Other)
KW  - ultrahigh field (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:35226966
DO  - DOI:10.1002/nbm.4722
UR  - https://inrepo02.dkfz.de/record/178969
ER  -